I think the act of optimization is the primary enjoyment a lot of optimizers get out of it. The fact that they have squeezed every bit of oomph out of a character is probably more important than actually getting to do so. The Giant in the Playground boards are full of builds that clearly never actually saw use in an actual game, for instance.
In a sense, I’m like a bizarro optimizer especially in D&D. I optimize my PCs to be the best versions of
themselves, not the best DPR machines. Clarifying: almost regardless of system, I try to make the mechanical character changes over time (i.e. leveling, build point expenditures, etc.) based on what
the character would want.
So, for instance, when I played a githzerai monk PC who used a polearm (as a monk weapon), all of the combat improvements made to him over time were centered on using that polearm. Early on, he did more damage than the party’s barbarian. But later, he was more effective at controlling the battlefield (reach weapon + the combat reflexes feat tree), keeping spellcasters safe from melee attackers.
Likewise, I ran a beefy Sorcerer whose obsession with his blue dragon ancestors meant the only attack spells he learned were electrical/lighting based, he channeled spell energy into a lightning breath weapon, used a maul (a weapon he carried as a bouncer in a brothel) and wore scale armor. If we ran into anything immune to his magic, he was swinging that maul in melee.
Those aren’t outliers. That’s core to how I’ve approached the hobby for the past couple of decades.
Hell- I was the same way with M:tG. I never played a “net deck”, but I’m partially responsible for changing the way some others designed their decks. Nobody who knew me wanted to draw me in a tournament.